Brew - reinstalling python@2

问题

I have been having issues with openssl and python@2 with brew, which have explained here (unresolved). The documented workaround to reinstall Python and openssl was not working, so I decided I would uninstall and reinstall Python.

The problem is, when you try to install Python 2 with brew, you receive this message:

brew install python@2
Error: No available formula with the name "python@2"
==> Searching for a previously deleted formula (in the last month)...
Warning: homebrew/core is shallow clone. To get complete history run:
  git -C "$(brew --repo homebrew/core)" fetch --unshallow

python@2 was deleted from homebrew/core in commit 028f11f9e:
  python@2: delete (https://github.com/Homebrew/homebrew-core/issues/49796)
  EOL 1 January 2020.
  We gave it 1 month more to live so that people had time to migrate.
  All in all, developers had 11 years to do their migration.
  You can use the `brew extract` command and maintain python@2 in your own
  tap if necessary:
  https://docs.brew.sh/How-to-Create-and-Maintain-a-Tap

To show the formula before removal run:
  git -C "$(brew --repo homebrew/core)" show 028f11f9e^:Formula/python@2.rb

If you still use this formula consider creating your own tap:
  https://docs.brew.sh/How-to-Create-and-Maintain-a-Tap

Unfortunately I still have a number of brew formulas that depends on Brew's python@2. Those include awscli, letsencrypt, pr sshuttle for example

aws
zsh: /usr/local/bin/aws: bad interpreter: /usr/local/opt/python@2/bin/python2.7: no such file or directory

I don't know how to use this brew extract command they documented to reinstall Python@2. It needs a formula and a tap. I imagine the formula would be python@2. I'm not sure what the tap would need to be.

Additionally reinstalling the taps such as aws or letsencrypt is not working very well either.

After reinstalling awscli (brew reinstall awscli), running aws commands still gives errors.

aws
/usr/local/Cellar/awscli/2.0.0/libexec/lib/python3.8/site-packages/jmespath/visitor.py:32: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if x is 0 or x is 1:
/usr/local/Cellar/awscli/2.0.0/libexec/lib/python3.8/site-packages/jmespath/visitor.py:32: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if x is 0 or x is 1:
/usr/local/Cellar/awscli/2.0.0/libexec/lib/python3.8/site-packages/jmespath/visitor.py:34: SyntaxWarning: "is" with a literal. Did you mean "=="?
  elif y is 0 or y is 1:
/usr/local/Cellar/awscli/2.0.0/libexec/lib/python3.8/site-packages/jmespath/visitor.py:34: SyntaxWarning: "is" with a literal. Did you mean "=="?
  elif y is 0 or y is 1:
/usr/local/Cellar/awscli/2.0.0/libexec/lib/python3.8/site-packages/jmespath/visitor.py:260: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if original_result is 0:
usage: aws [options] <command> <subcommand> [<subcommand> ...] [parameters]
To see help text, you can run:

  aws help
  aws <command> help
  aws <command> <subcommand> help
aws: error: the following arguments are required: command

回答1:

It seems that the homebrew staff really makes it as hard as possible to use Python 2.7 on macOS as they can.

The linked brew extract link is really not helpful, you need to look for answers here about how to make your own tap from extracted sources.
The linked commit: 028f11f9e is wrong, as it contains the already deleted file.
The brew extract command doesn't even work correctly, because of the @ in the package name.

The solution is very simple though, you just need to install from the latest known commit:

brew install https://raw.githubusercontent.com/Homebrew/homebrew-core/86a44a0a552c673a05f11018459c9f5faae3becc/Formula/python@2.rb

There is a warning about this being "unstable", which I don't understand as a commit in a Git history is as stable as you can get.

来源：https://stackoverflow.com/questions/60298514/brew-reinstalling-python2

标签

python

macos

homebrew

python-2.x